Abstract :
Attentional capture is often regarded as a unitary phenomenon, which includes the exogenous capture of attention, by objects, colours, and motion. However an issue that has generated considerable controversy is whether colour-singletons can capture attention as effectively as sudden-onset objects appear to be able to. Here we present evidence which demonstrates that task-irrelevant, colour-changing stimuli can affect performance during visual search. However the pattern of reaction time costs and benefits strongly suggests this form of attentional capture is not the same as that by sudden-onset. While sudden-onset objects appear to cause a genuine shift in the allocation of attention, colour-changing stimuli merely cause a filtering cost. A similar pattern of results is found in luminance-change conditions.